Integrated precursor delivery system

ABSTRACT

An integrated precursor delivery system which integrates a precursor delivery system with a processing chamber is provided for improving the precursor delivery lines to the processing chamber, and for keeping the delivery lines intact during servicing the processing chamber. The apparatus provides an integrated precursor delivery system mounted on the processing chamber lid with the chamber lid being removable for allowing manual access to the inside of the processing chamber. With the precursor delivery system is in the close vicinity of the processing chamber, the delivery lines are shortest possible, minimizing the chance of precursor contamination. With the delivery system and the chamber lid in one unit, the removal of the chamber lid will no longer require breaking the delivery lines, leading to better contamination control. The present invention is particular suitable for liquid precursors since liquid is much more difficult to evacuate than gas. The invention further provides a hybrid system of integrated precursor delivery system and remote precursor delivery system. For gaseous precursors, especially non-reactive precursor such as nitrogen, argon, helium, the cleaning of the delivery line is very simple. Therefore a hybrid system of integrated and remote precursor delivery systems offers the best solution, an integrated precursor delivery system for the difficult-to-clean precursors, and a remote precursor delivery system for the easy-to-clean precursors.

[0001] This application is a continuation-in-part of application Ser.No. 09/596,517, filed Jun. 19, 2000.

FIELD OF THE INVENTION

[0002] The present invention relates generally to apparatus forprocessing of a semiconductor wafer, and more particularly to aprocessing chamber with integrated precursor delivery system.

BACKGROUND OF THE INVENTION

[0003] Conventional chemical vapor deposition (CVD) processes useprecursors for the deposition of thin films on an IC substrate.Precursors can be classified as reactive precursors and non-reactiveprecursors. Reactive precursors are chemical species to undergo areaction for the processing of the thin film. Non-reactive precursorsare not reactive, and often used to dilute the reactive precursor or tocarry the reactive precursors to the processing chamber. Suchnon-reactive precursor is called a carrier gas. Traditionally,precursors used in semiconductor processes are gaseous. To broaden theprocesses, more and more liquid and solid precursors have been used,especially in the area of metal-organic chemical vapor deposition(MOCVD). To perform this task, a liquid precursor is typically turned tovapor, and the vapor is then decomposed on the substrate. A solidprecursor must often be dissolved into a solvent to form a liquidprecursor. Then, the liquid precursor needs to be converted into vaporphase before introduction into the deposition zone.

[0004] The simplest form of liquid precursor delivery system is to drawthe vapor from the liquid precursor. This technique works well with highvolatile liquid with high vapor pressure. The liquid precursor can alsobe heat up to further increasing the vapor pressure. The liquid deliveryline then needs to be heating up for preventing re-condensation. Anothertechnique to increase the amount of vapor precursor of a liquidprecursor is bubbling. A non-reactive precursor, often called a carriergas, is bubbled through the liquid precursor. The carrier gas thencarries the vapor precursor to the processing chamber.

[0005] However, to have high deposition rate with low vapor pressureprecursors, a direct liquid injection system is required. Basiccomponents of a direct liquid injection system are a liquid deliveryline and a vaporizer. The liquid delivery line carries the liquidprecursor from the liquid container to the vaporizer. The vaporizerconverts the liquid precursor into vapor form before delivering on thewafer substrate. A carrier gas is normally used in the vaporizer tocarry the precursor vapor to the substrate. In some applications, areactive precursor could take place of the carrier gas, performing thecarrying function together with a chemical reaction.

[0006]FIG. 1 shows a prior art gaseous precursor delivery system. Theprecursor 13 is stored in gaseous form in the container 12, often underhigh pressure. The delivery line 11 is used to take the precursor out ofthe container to the processing chamber. A heater means 14 is used toheat the container 12 to increase the pressure of the precursor in thecontainer.

[0007]FIG. 2 shows a prior art liquid precursor delivery system. Theliquid precursor 23 is stored in the container 22 and having a certainvapor precursor 26 co-existing in the container. The heater means 24 isused to heat the container 22 to increase the precursor vapor pressure.The precursor delivery line 21 is used to take the precursor vapor outof the container to the processing chamber. A second heater means 25 isused to heat the delivery line to prevent condensation.

[0008]FIG. 3 shows a prior art solid precursor delivery system. Thesolid precursor 33 is stored in the container 32 and having a certainvapor precursor 36 co-existing in the container. The heater means 34 isused to heat the container 32 to increase the precursor vapor pressure.The precursor delivery line 31 is used to take the precursor vapor outof the container to the processing chamber. A second heater means 35 isused to heat the delivery line to prevent condensation.

[0009]FIG. 4 shows another prior art liquid precursor delivery system.The liquid precursor 43 is stored in the container 42 and having acertain vapor precursor 46 co-existing in the container. The heatermeans 44 is used to heat the container 42 to increase the precursorvapor pressure. A carrier gas 47 is used to bubble through the liquidprecursor to increase the precursor vapor through the delivery line 41.The precursor delivery line 41 is used to take the precursor vapor outof the container to the processing chamber. A second heater means 45 isused to heat the delivery line to prevent condensation.

[0010]FIG. 5 shows another prior art liquid precursor delivery system.This system injects the liquid precursor 53 through the delivery line51, and then converts the liquid to vapor form in the vaporizer 58. Theliquid precursor 53 is stored in the container 52 and having a certainvapor precursor 56 co-existing in the container. A carrier gas 57 isused to push the liquid precursor to the delivery line 51. The precursordelivery line 51 is used to take the precursor liquid out of thecontainer to the vaporizer 58. A heater means 59 is used to heat thevaporizer 58 to convert the liquid precursor to vapor form.

[0011] In these drawings, all controlled valves have been omitted forclarity. Such valves are used to control the start, stop and even theflow rate of the precursor.

[0012] The precursor delivery system delivers the precursor vapor to aprocessing chamber, typically to the chamber lid, where the precursorvapor will react at a wafer surface. The precursor by-products are thenpumped out to the exhaust. The precursor delivery line often has ashowerhead to distribute the precursor vapor evenly on the wafersurface. The precursor delivery system is mounted in a remote locationfrom the processing chamber, and having an enclosure with an exhaust fanto prevent the accidental leakage of the precursor to the environment.Typical processing chamber has a removable chamber lid to allow manualaccess to the inside of the processing chamber such as repair orservicing the inside of the processing chamber. Therefore the remoteprecursor delivery system will need to have the delivery line broken toremove the chamber lid.

[0013]FIG. 6 shows a prior art remote precursor delivery system. Theprecursor 143 is stored in the precursor container 142, and will travelsthrough the precursor delivery line 141 to the chamber lid 110. Thechamber lid 110 has an inlet port to the inside of the processingchamber, in this case a showerhead 120. The chamber lid 110 is removablefrom the chamber body 112 at the connection 114. Since the delivery line141 is solid, to remove the chamber lid 110 means breaking the deliveryline at the connection 130. Before breaking the connection 130, thedelivery line needs to be clean to avoid contaminating the environment.After re-connect the connection 130, the delivery line needs to be cleanagain to avoid contaminating the precursor. These cleaning procedure istime consuming and difficult, especially for liquid precursor. It isbest to replace the liquid delivery line, or at the very least, clean insolvent and bake out at high temperature to remove moisture, every timethe connection 130 is broken.

[0014]FIG. 7 shows another prior art remote precursor delivery system.The chamber lid 110 is removable from the chamber body 112 at theconnection 114. Connection 114 also includes a mating o-ring connection160 between the chamber lid 110 and the chamber body 112 for thedelivery line. This way when the chamber lid is removed, the deliveryline is automatically broken. As with FIG. 6 configuration, thisconfiguration also requires cleaning of the delivery line before andafter breaking the connection 160.

[0015]FIG. 8 shows another prior art remote precursor delivery system.The delivery line 141 includes a loop section 140 to allow limitedmovement of the chamber lid 110 without breaking the delivery line 141.Similarly, the delivery line 141 of FIG. 9 configuration includes aflexible section 150 to allow limited movement of the chamber lid 110without breaking the delivery line 141. The advantage of these twoconfigurations is that the delivery line 141 remains intact during theremoval of the chamber lid 110. The disadvantages are the extra lengthof the delivery line and its long term reliability. In fact, the movabledelivery line is not popular in many equipment vendors.

[0016] It would be advantageous if a precursor delivery line remainsintact during the removal of the chamber lid.

[0017] It would be advantageous if a precursor delivery line does notmove during the removal of the chamber lid.

SUMMARY OF THE INVENTION

[0018] Accordingly, an integrated delivery processing chamber apparatusis provided to maintaining the delivery line intact during the removalof the chamber lid. In the present invention, the precursor deliverysystem is mounted to the chamber lid, therefore the delivery line andthe chamber lid move together as one unit. An additional benefit of thepresent invention is the short delivery line since the precursordelivery system and the processing chamber is very close to each other.

[0019] The present invention integrated precursor delivery systemapparatus which integrates a precursor delivery system with a processingchamber comprises:

[0020] a hollow processing chamber comprising a removable chamber lidfor allowing manual access to the inside of the processing chamber;

[0021] an integrated precursor delivery system mounted to the chamberlid and operatively connected to the chamber lid, the precursor deliverysystem comprising:

[0022] a precursor container for containing the precursor;

[0023] a precursor delivery line;

[0024] whereby the precursor delivery line delivers the precursor fromthe precursor container to the processing chamber with the precursordelivery line remains intact during the removal of the chamber lid.

[0025] The output of the precursor delivery system is connected to thechamber lid to provide the precursor vapor to the processing chamber. Insome aspects of the invention, to improve the uniformity of theprecursor distribution, the chamber lid comprises a showerhead connectedto the output of the precursor delivery system. The precursor deliverysystem further comprises various valves to allow the control of theprecursor flow.

[0026] In some aspects of the invention, the apparatus further comprisesa system heater means to heat the precursor delivery system or to heatthe precursor delivery line.

[0027] In some aspects of the invention, the precursor is in solid form,and the precursor delivery line carries only the precursor vapor fromthe precursor container to the processing chamber. In some aspects ofthe invention, the precursor is in gaseous form, and the precursordelivery line carries the gaseous precursor from the precursor containerto the processing chamber. In some aspects of the invention, theprecursor is in liquid form, and the precursor delivery line carriesonly the precursor vapor from the precursor container to the processingchamber. Sometimes the precursor delivery system further comprises acarrier gas system to help carrying the precursor vapor from theprecursor container to the processing chamber.

[0028] In some aspects of the invention, the precursor is in liquidform, and the precursor delivery line carries the precursor liquid fromthe precursor container to the processing chamber. The precursordelivery system further comprises a vaporizer to convert the liquidprecursor to vapor form before reaching to the processing chamber. Theprecursor delivery system further comprises a precursor metering deviceto control the precursor flow rate from the precursor container to theprocessing chamber. The precursor metering device could be a liquidpump, a liquid flow controller to measure the liquid flow, or a massflow controller to measure the gas flow.

[0029] In some aspects of the invention, the precursor delivery systemfurther comprises a precursor refilling system for refilling theprecursor container. The precursor refilling system could compriseflexible refilling lines to accommodate the movement of the chamber lid.Or the precursor refilling system line will need to be broken to removethe chamber lid. Since the refilling line will not be used as much asthe delivery line, the cleaning of the refilling line before and afterthe breakage will not be frequent.

[0030] In some aspects of the invention, the apparatus further comprisesa plurality of precursor delivery systems. These multiple precursordelivery systems could share the same output manifold to the chamberlid. Various processes require multiple precursors and multiple separateprecursor delivery systems.

[0031] In some aspects of the invention, the apparatus further comprisesa remote precursor delivery system. In some aspects of the invention,the remote precursor delivery system provides gaseous precursor. Forliquid injection, or bubbling system, a carrier gas is needed. Since thecarrier gas is often inert gas, this line does not need the extensivecleaning before and after the line breakage. The remote precursordelivery line could comprise flexible lines or mating o-ring between thechamber lid and the chamber body to accommodate the movement of thechamber lid.

[0032] In some aspects of the invention, the precursor delivery systemfurther comprises an enclosure for capturing potential precursorleakage. The precursors could be toxic, therefore an enclosure with anexhaust fan helps in the unlikely scenario of precursor leakage.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 shows a prior art compressed gaseous precursor deliverysystem.

[0034]FIG. 2 shows a prior art liquid precursor delivery system withvapor delivery line.

[0035]FIG. 3 shows a prior art solid precursor delivery system withvapor delivery line.

[0036]FIG. 4 shows a prior art liquid precursor delivery system withvapor delivery line and bubbling system.

[0037]FIG. 5 shows a prior art liquid precursor delivery system withliquid delivery line and vaporizer.

[0038]FIG. 6 shows a prior art remote precursor delivery system withbreakable precursor delivery line.

[0039]FIG. 7 shows another prior art remote precursor delivery systemwith breakable precursor delivery line.

[0040]FIG. 8 shows a prior art remote precursor delivery system withmovable precursor delivery line.

[0041]FIG. 9 shows another prior art remote precursor delivery systemwith movable precursor delivery line.

[0042]FIG. 10 shows the present invention integrated precursor deliverysystem.

[0043]FIG. 11 shows another aspect of the present invention integratedprecursor delivery system.

[0044]FIG. 12 shows another aspect of the present invention integratedprecursor delivery system using liquid precursor bubbler.

[0045]FIG. 13 shows another aspect of the present invention integratedprecursor delivery system using liquid precursor vapor phase draw.

[0046]FIG. 14 shows another aspect of the present invention integratedprecursor delivery system using solid precursor bubbler.

[0047]FIG. 15 shows another aspect of the present invention integratedprecursor delivery system using solid precursor vapor phase draw.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT

[0048]FIG. 10 shows the present invention integrated precursor deliverysystem. The present invention integrates a precursor delivery systemwith a processing chamber for the ease of servicing the processingchamber. Added benefits are shorter delivery line, and compact andmodular system. The invention provides a precursor delivery system 141,142, 143 mounted on a removable chamber lid 110. The precursor deliverysystem comprises a precursor container 142 to contain the precursor 143,and a precursor delivery line 141 to deliver the precursor 143 from theprecursor container 142 to the processing chamber. The processingchamber comprises a chamber body 112 and a removable chamber lid 110.The chamber lid 110 can be removed from the processing chamber at theconnection 114 for servicing the inside of the processing chamber. Theprecursor delivery line 141 is operatively connected to the chamber lid110 to delivering the precursor to the inside of the processing chamber.An optional showerhead 120 is connected to the precursor delivery line141 for better precursor distribution. With the precursor deliverysystem mounted to the chamber lid, the removal of the chamber lid willalso move the precursor delivery system, thus the precursor deliveryline remains intact.

[0049]FIG. 11 shows another aspect of the present invention integratedprecursor delivery system. The system is a hybrid of integratedprecursor delivery system and remote precursor delivery system. Thecleaning of liquid delivery line to ensure no contamination is verydifficult and time consuming, thus an integrated precursor deliverysystem is well suited for liquid precursors. The major disadvantage ofthe integrated precursor delivery system is that there is not enoughroom at the chamber lid to accommodate all the delivery components.However, for gaseous precursors, especially non-reactive precursor suchas nitrogen, argon, helium, the cleaning of the delivery line is verysimple. A few pump/purge cycles of the delivery line should be adequate.Therefore a hybrid system of integrated and remote precursor deliverysystems offers the best solution, an integrated precursor deliverysystem for the difficult-to-clean precursors, and a remote precursordelivery system for the easy-to-clean precursors. The integrated liquidprecursor delivery system is mounted to the chamber lid 310 and theremote gaseous precursor delivery systems provide gaseous precursor 357and 375 to the chamber lid 310 through the mated o-ring connections 360and 361 respectively. The gaseous precursor 357 is a pushing gas, usedto push the liquid precursor 353 in the liquid precursor container 352.The liquid precursor travels through the liquid precursor delivery line351 to a metering device 370 to control the precursor flow rate. Theliquid precursor is then vaporized in the vaporizer 358. The vaporizer358 is heated to a vaporizer temperature by a heater 359. An optionalremote precursor 375 is provides to the output of the vaporizer 358 andto the processing chamber. The precursor delivery system is enclosed inan enclosure 380 having an exhaust port 384 to protect the environmentfrom accidental release of precursors.

[0050]FIG. 12 shows another aspect of the present invention integratedprecursor delivery system using liquid precursor bubbler. The integratedliquid precursor delivery system is mounted to the chamber lid and theremote gaseous precursor delivery systems provide gaseous precursor tothe chamber lid through the mated o-ring connections. The gaseousprecursor 457 is a carrier gas, used to bubbling the liquid precursor453 in the liquid precursor container 452. The carrier gas and theliquid precursor vapor travels through the liquid precursor deliveryline 451 to a metering device 470 to control the precursor vapor flowrate. The liquid precursor vapor is then entering the showerhead to thechamber body. The liquid precursor delivery line is heated by a heater459A. The liquid precursor container 452 is heated by a heater 459B to aprecursor temperature to increase the vapor pressure. An optional remoteprecursor can provide precursor mixing with the liquid precursor vaporto the processing chamber.

[0051]FIG. 13 shows another aspect of the present invention integratedprecursor delivery system using liquid precursor vapor phase draw. Theintegrated liquid precursor delivery system comprising a liquidprecursor container 552 containing liquid precursor 553 and is mountedto the chamber lid. The liquid precursor vapor is drawn to the liquidprecursor delivery line 551 to a metering device 570 to control theprecursor vapor flow rate. The liquid precursor vapor is then enteringthe showerhead to the chamber body. The liquid precursor delivery lineis heated by a heater 559A. The liquid precursor container 552 is heatedby a heater 559B to a precursor temperature to increase the vaporpressure. An optional remote precursor can provide precursor mixing withthe liquid precursor vapor to the processing chamber.

[0052]FIG. 14 shows another aspect of the present invention integratedprecursor delivery system using solid precursor bubbler. The integratedprecursor delivery system is mounted to the chamber lid and the remotegaseous precursor delivery systems provide gaseous precursor to thechamber lid through the mated o-ring connections. The gaseous precursor657 is a carrier gas, used to bubbling the solid precursor 653 in thesolid precursor container 652. The carrier gas and the solid precursorvapor travels through the precursor delivery line 651 to a meteringdevice 670 to control the precursor vapor flow rate. The solid precursorvapor is then entering the showerhead to the chamber body. The precursordelivery line is heated by a heater 659A. The solid precursor container652 is heated by a heater 659B to a precursor temperature to increasethe vapor pressure. An optional remote precursor can provide precursormixing with the solid precursor vapor to the processing chamber.

[0053]FIG. 15 shows another aspect of the present invention integratedprecursor delivery system using solid vapor phase draw. The integratedprecursor delivery system comprising a solid precursor container 752containing solid precursor 753 and is mounted to the chamber lid. Thesolid precursor vapor is drawn to the precursor delivery line 751 to ametering device 770 to control the precursor vapor flow rate. The solidprecursor vapor is then entering the showerhead to the chamber body. Theprecursor delivery line is heated by a heater 759A. The solid precursorcontainer 752 is heated by a heater 759B to a precursor temperature toincrease the vapor pressure. An optional remote precursor can provideprecursor mixing with the liquid precursor vapor to the processingchamber.

[0054] Although a preferred embodiment of practicing the method of theinvention has been disclosed, it will be appreciated that furthermodifications and variations thereto may be made while keeping withinthe scope of the invention as defined in the appended claims.

What is claimed is:
 1. An integrated precursor delivery system apparatuswhich integrates a precursor delivery system with a processing chamber,the apparatus comprising: a hollow processing chamber comprising aremovable chamber lid for allowing manual access to the inside of theprocessing chamber; a liquid precursor container mounted on the chamberlid for storing the precursor in bulk liquid form; a carrier gas systemconnected to an inlet of the liquid precursor container; and a precursordelivery line communicated with the liquid precursor container and theprocessing chamber; whereby the precursor delivery line deliversvaporized precursor and carrier gas from the liquid precursor containerto the processing chamber with the precursor delivery line remainingintact during the removal of the chamber lid.
 2. An apparatus as inclaim 23 further comprising a precursor heater to heat the precursorcontainer.
 3. An apparatus as in claim 23 in which the precursordelivery system further comprises a delivery line heater to heat theprecursor delivery line.
 4. An apparatus as in claim 23 in which theprecursor delivery system further comprises a precursor metering deviceto control the flow rate of the vaporized precursor and carrier gas. 5.An apparatus as in claim 26 in which the precursor metering device is amass flow controller.
 6. An apparatus as in claim 23 further comprisinga precursor refilling system for refilling the liquid precursorcontainer.
 7. An apparatus as in claim 28 in which the precursorrefilling system comprising flexible refilling lines to accommodate themovement of the chamber lid.
 8. An apparatus as in claim 23 furthercomprising a plurality of integrated precursor delivery systems.
 9. Anapparatus as in claim 23 further comprising a remote precursor deliverysystem.
 10. An apparatus as in claim 31 in which the remote precursordelivery system provides gaseous precursor.
 11. An apparatus as in claim31 in which the remote precursor delivery system comprises flexiblelines to accommodate the movement of the chamber lid.
 12. An apparatusas in claim 31 in which the remote precursor delivery system comprisesan o-ring seal between the chamber lid and the rest of the hollowprocessing chamber to accommodate the movement of the chamber lid.